<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="valAll" /> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <Cart v-for="(item, index) in goodList" :key="index" :name="item.name" :price="item.price" :num="item.num" :index="index" :checked="item.checked"  @harry="harryFn"  @delbtn="delFn"
          @checked="checkedFn"></Cart>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:</td>
          <td colspan="5">{{totle}}</td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
import Cart from './components/Cart.vue'
export default {
  watch: {
    goodList: {
      immediate: true,
      deep: true,
      handler(newVal) {
        this.totle = newVal.reduce((sum, item) => sum + item.num * item.price, 0)
      },
    },
  },
  computed: {
    valAll: {
      set(val) {
        this.goodList.forEach((item) => (item.checked = val))
      },
      get() {
        return this.goodList.every((item) => item.checked)
      },
    },
  },
  data() {
    return {
      val: false,
      goodList: [
        {
          name: '诸葛亮',
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: '蔡文姬',
          price: 1500,
          num: 1,
          checked: false,
        },
        {
          name: '妲己',
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: '鲁班',
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
      totle:0
    }
  },
  components: { Cart },
  methods: {
    harryFn(index, n) {
      if (this.goodList[index].num >= 0 && n > 0) this.goodList[index].num += n
      if (this.goodList[index].num >= 1 && n < 0) this.goodList[index].num += n
    },
    delFn(index) {
      this.goodList.splice(index, 1)
    },
    checkedFn(index) {
      this.goodList[index].checked = !this.goodList[index].checked
    },
  }
}
</script>

<style></style>